Method, apparatus, system, computer program and computer program products for providing a plmn identifier to a node of a ran

ABSTRACT

A method in a communication system includes a first core network node (CN), a second CN, a base station apparatus serving a user equipment (UE), and a packet data network gateway (PGW) associated with the UE, the method being performed by the first CN. The method includes the first CN receiving a tunneling endpoint identifier (TEID) information element from a second CN, the TEID information element comprises a plurality of fields. The one of the plurality of fields includes a Public Land Mobile Network (PLMN).

CROSS REFERENCE TO RELATED APPLICATION(S)

This application claims the benefit of U.S. Provisional Application No.61/827,343, filed May 24, 2013, which in turn claims priority toInternational Application No. PCT/EP2014/060477, filed on 21 May 2014,both of which are incorporated herein by reference.

TECHNICAL FIELD

This disclosure relates to providing a PLMN identifier to a node of aradio access network (RAN).

BACKGROUND

A RAN can improve its management of radio resources by knowing servicescurrently being used by wireless communication devices (referred toherein as “user equipment (UE)”) that are served by the RAN. In 3GPP,such a function is called SIRIG (which stands for Service identificationfor improved radio utilization for GERAN), where the serviceidentification is provided to the RAN (e.g., provided to a base stationof the RAN or a radio network controlling in the RAN) by a core networknode (CN) comprising a Mobility Management Entity (MME) or a servingGPRS support node (SGSN).

While SIRIG is currently only defined for GERANs (GSM EDGE Radio AccessNetworks), SIRIG can be extended to other radio access technologies(RATs), e.g., universal mobile telecommunications system (UMTS), longterm evolution (LTE), etc.

SUMMARY

According to an aspect of the present invention, a method in acommunication system includes a first core network node (CN), a secondCN, a base station apparatus serving a user equipment (UE), and a packetdata network gateway (PGW) associated with the UE, the method beingperformed by the first CN. The method includes the first CN receiving atunneling endpoint identifier (TEID) information element form a secondCN, the TEID information element comprises a plurality of fields. Theone of the plurality of fields includes a Public Land Mobile Network(PLMN) identifier of the PGW. The method further includes the first CNforwarding the received PLMN identifier to the base station apparatus.

According to another aspect of the present invention, a method in acommunication system includes an SGSN, a base station serving a userequipment (UE), an RNC controlling the base station, and a packet datanetwork gateway (PGW) associated with the UE, the method being performedby the SGSN. The method includes the SGSN obtaining a PLMN identifier(ID) of the PGW. The method further includes the SGSN transmitting thePLMN ID to the RNC.

According to another aspect of the present invention, a method in acommunication system includes a first core network node (CN), a basestation apparatus serving a user equipment (UE), and a packet datanetwork gateway (PGW) associated with the UE, the method being performedby the first CN. The method includes the first CN obtaining a PLMNidentifier of the PGW. The method further includes the first CNtransmitting a message to the base station apparatus. The messageincludes: (i) an information element containing the PLMN ID of the PGW;and (ii) a radio access bearer (RAB) identifier information elementincluding data identifying a RAB.

According to another aspect of the present invention, a method in acommunication system includes a first core network node (CN), a secondCN, and a packet data network gateway (PGW) associated with userequipment (UE). The method is performed by the first CN and includes thefirst CN encoding a Public Land Mobile Network identifier (PLMN ID) ofthe PGW in a TEID/GRE Key field of a F-TEID information element. Themethod further includes the first CN transmitting the F-TEID informationelement containing the PLMN ID to the second CN.

The SIRIG function supports both roaming and network sharing scenarios.(See SP-120252 and SP-120483). The solution to support the roamingscenario is specified in section 5.3.5.3 in 3GPP TS 23.060 as follows:

-   -   “When the serving A/Gb mode SGSN receives SCI in a GTP-U packet,        it copies it, without modifying its value, into a Gb interface        information element that is sent by the SGSN in the downlink Gb        interface user data packet to the GERAN access. In order to        allow the GERAN to map the SCI into RRM behaviour, the downlink        Gb interface user data packet also carries the HPLMN ID (in the        IMSI parameter) and additional information, added by the SGSN,        which indicates whether the SCI is assigned by a GGSN/P-GW in        e.g. the Home PLMN or Visited PLMN. Absence of additional        information is an indication of a VPLMN provided SCI    -   The A/Gb mode GERAN uses the information from the SGSN to        determine whether to map, and how to map, the SCI to the related        RRM behaviour. If the GERAN is not configured with an SCI        mapping for the SGSN provided information, then the GERAN shall        treat the user plane packet normally, i.e. the GERAN ignores the        SCI.    -   NOTE 4: When sending downlink GTP-U packets, there are some        transient periods where the “current RAT” information for the        user may be incorrect at the GGSN/P-GW e.g. after a handover        from (E)UTRAN to GERAN, or if the MS is in idle mode with ISR        active, or if the MS is in idle mode and located in a Routing        Area comprising GERAN and UTRAN cells. In these cases, the A/Gb        mode GERAN may receive the first downlink user plane packets        without Service Class Indicator.”

Thus, the BS based on the knowledge of the international mobilesubscriber identity (IMSI) and the additional information indicatingwhether the subscriber controlled input (SCI) is assigned by a GGSN/P-GW(e.g., the Home PLMN or Visited PLMN) interprets the semantics of SCIand apply relevant radio resource management (RRM) behaviors. But, theabove solution may have a problem when SIRIG function is extended to LTEand UMTS because the enodeB (eNB) has no knowledge of IMSI. Thereforethe solution doesn't work for LTE.

When Direct Tunnel is used in 3G or 4G is used, the payload path may beRNC/eNB -SGW -PGW, which indicates that the SGW has to insert such“additional information indicating whether the SCI is assigned by aGGSN/P-GW in e.g. the Home PLMN or Visited PLMN.” When Direct Tunnel isnot used, the payload path would be RNC-SGSN-SGW-PGW, which indicatesthat the SGSN has to insert such “additional information indicatingwhether the SCI is assigned by a GGSN/P-GW in e.g. the Home PLMN orVisited PLMN.”.

Because both RNC and eNB support the Bearer Service concept (where theUMTS bearer service is specified in 3GPP TS 23.107 and EPS bearer isspecified in the section 4.7 in TS 23.401), the SGW or MME/SGSN caninform RNC or eNB about PLMN of the PGW (i.e., the PLMN in which the PGWis located) for each bearer contexts within a given PDN connection. TheSGW or MME/SGSN can inform RNC/eNB about the PLMN of the PGW during, forexample, RAB assignment procedure and SRNS relocation procedure in 3G(or during initial UE context setup/E-RAB establishment and handoverprocedure in LTE). Both RNC and eNB have no PDN connection level conceptbut only bearer context within a PDN connection.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates an example communication system 100 in whichembodiments of this disclosure are implemented;

FIGS. 2-8, 9A and 9B illustrates example flows in which embodiments ofthis disclosure are implemented; and

FIG. 10 illustrates an example block diagram of an example core networknode.

DETAILED DESCRIPTION

This disclosure relates to providing a PLMN identifier to a node of aradio access network (RAN). In embodiments, the present inventionenables roaming support for SIRIG when it is used for UMTS and LTE.Thus, comparing with the existing solution, one or more embodiment aremuch more efficient as the PLMN information of the PGW is provided perbearer context, not per GTP-U packet, which reduces very much processingload in eNB 114, RNC 106, SGSN 108, SGW 118, as shown in FIG. 1. Thedisclosure also allows for transfer of information during handoverprocedures, useful for SIRIG solutions in UTRAN and E-UTRAN.

I. Embed PLMN Identifier in the User Plane Address

Before user plane data can be transferred to the UE 128 (see FIG. 1), auser plane path, i.e., a bearer has to be established. The bearerestablishment may happen during one or more of the following procedures:Initial attach (in E-UTRAN 112 in FIG. 1), TAU with Active flag, PDPContext Activation, RAU with Follow-on-request flag, SRNS relocation(RAB need to be established in the target RAN before UE is moving in),etc.

The SGW 118 (3G when DT is used or 4G for EPS), the SGSN 108 (when DT isnot used in 3G), or the GGSN 110 (3G when DT is used but it is connectedwith Gn/Gp SGSN), will provide user plane transportation address (IPaddress+TEID=F-TEID) to the RAN via the MME 116/SGSN 108 (through S1-MMEand Iu interface).

For 3G and when direct tunnel is used (or for 4G), the SGW will provideSGW F-TEID(s) for the user plane for each bearer context. The F-TEID(s)will be forwarded by the SGSN 108 or the MME 116 during RAB assignmentprocedure or during initial UE context setup/E-RAB establishmentprocedure to the RNC 106 or the eNB 114. Those SGW F-TEID(s) are used byRNC 106 and eNB 114 to send any uplink user plane data. During SRNSrelocation procedure in 3G or handover procedure in LTE, the target SGSN108 or MME 116 provides the SGW 118 user plane F-TEID either receivedfrom the source MME 116/SGSN 108 (in case the SGW is not relocated) orfrom a new SGW (in case the SGW is relocated).

This disclosure proposes that the SGW 118 embed a PLMN identifier (PLMNID) into the SGW F-TEID when it is sent to the MME 116/SGSN 108, wherethe embedded PLMN ID identifies the PLMN of the PGW 120 (i.e., the PLMNin which the PGW is located) associated with the UE 128. This isillustrated in FIG. 2, which shows the SGW 118 receiving a createsession request message from an MME 116 (or SGSN 108) and thentransmitting a create session response message to the MME 116/SGSN 108,which creates a session response message that includes an F-TEIDinformation element that contains a field containing the PLMN ID.

F-TEID is an existing information element as specified in section 8.22TS 29.274 as follows:

-   -   8.22 Fully Qualified TEID (F-TEID)    -   Fully Qualified Tunnel Endpoint Identifier (F-TEID) is coded as        depicted in FIG. 8.22-1.

FIG. 8.22-1: Fully Qualified Tunnel Endpoint Identifier (F-TEID) BitsOctets 8 7 6 5 4 3 2 1 1 Type = 87 (decimal) 2 to 3 Length = n 4 SpareInstance 5 V4 V6 Interface Type 6 to 9 TEID/GRE Key m to (m + 3) IPv4address p to (p + 15) IPv6 address k to (n + 4) These octet(s) is/arepresent only if explicitly specified

The Octets 6-9 (a.k.a., the TEID/GRE Key field) is encoded for TEID,where PLMN ID of the PGW 120 may be embedded according to an operator'sconfiguration. That is, the PLMN ID of the PGW 120 may be encoded in theTEID/GRE Key field of the F-TEID information element.

For 3G when direct tunnel is not used, the SGSN 108 will provide SGSNF-TEID to the RNC 106 during RAB assignment procedure (this isillustrated in FIG. 3). Accordingly, the SGSN 108 can embed PLMNinformation of the PGW 120 for a given PDN connection into SGSN F-TEID,as described above.

For legacy Gn/Gp SGSN interworking with a GGSN in another PLMN whendirect tunnel is used, the GGSN may embed PLMN ID of the GGSN for agiven PDP into GGSN TEID on the user plane, which will be forwarded bythe Gn/Gp SGSN to the RNC 106 as described in FIG. 4. Stage 2 changes tocurrent specifications may be needed in order to describe that the TEIDforwarded to RNC 106 or eNB contains information about the HPLMN ID orVPLMN ID corresponding to the PGW 120 where the RAB is established.

When indirect data forwarding is used during handover/SRNS relocationprocedure and when the SGW 118 selected as data forwarding is NOT theanchor SGW, the forwarding SGW has no knowledge of PLMN information ofthe PGW 120, thus those packets received via indirect tunneling may notassociated with a PLMN information, hence they may not be correctlyhandled. This requires when setting up the indirect tunnel, the SGSN108/MME 116 shall either not use non-anchor SGW, or shall let the dataforwarding SGW know about PLMN information of PGW 120. This implies aprotocol change—to add PLMN information of the PGW 120 in the GTPmessage “Create Indirect Data Forwarding Tunnel Request message”, sowhen data forwarding SGW 118 allocates SGW F-TEID for data forwarding,it can embed such PLMN information of the PGW into the SGW F-TEID.

II. Provide PLMN ID During Bearer Establishment

It is also possible to provide the PLMN ID of the PGW 120 serving the UE128 to the RNC 106 or eNB 114 during RAB assignment procedure and SRNSrelocation procedure (for 3G) or Initial UE context setup/E-RABestablishment procedure and handover procedure (for 4G), by the SGSN 108or MME 116.

The procedure for RAB assignment procedure for 3G is described in thesection 12.7.4.1 of TS 23.060 RAB Assignment Procedure Using Gn/Gp andin the section 8.2.2 of TS 25.413 and illustrated in FIG. 5.

In the RAB Assignment Request message, a new IE, preferably called “PLMNof PGW/GGSN” is included, and associated with each RAB. Addition of thenew PLMN of PGW/GGSN IE in the RAB Assignment Request message is shownin Table 1. FIG. 6 illustrate a core network node (CN) transmitting amessage of type RAB assignment request to an RNC 106. The RAB assignmentrequest message includes the PLMN ID of the PGW serving the UE that theRAB identified in the message is for.

An MME may provide to an eNB 114 the PLMN ID using a message of typeInitial Context Setup Request, as shown in FIG. 7. Addition of the newPLMN of PGW/GGSN IE in the INITIAL COTEXT SETUP message is shown inTable 2.

An MME 116 may provide to an eNB 114 the PLMN ID using a message of typeE-RAB Setup Request, as shown in FIG. 8. Addition of the new PLMN of PGW120/GGSN 110 IE in the E-RAB SETUP REQUEST message is shown in Table 3.Once the PLMN of PGW 120/GGSN 110 has been transferred to the servingRAN according to the embodiment above, there is also the need totransfer such information during handover procedures across differentbase stations. This should be done both for UTRAN 102 and E-UTRAN 112and both for network based handovers (i.e. S1 or RANAP handovers) ordirect interface handovers such as X2 or Iur handovers. The S1 handoverprocedure for E-UTRAN 112 is described in TS23.401 section 5.5.1.2.2 andas is shown in FIGS. 9A and 9B. In alternate embodiments, an equivalentprocedure exists for UTRAN RANAP based handovers.

In addition, when indirect tunneling is applicable, the target RANshould apply the received PLMN of the PGW 120 via Handover Request andRelocation Request also to that associated data forwarding tunnel.

The new PLMN of PGW IE shall be added to the HANDOVER REQUEST message tocommunicate to the target RAN the PLMN ID of the PGW associated to thehanded over RAB. An example of how such new IE could be included isshown in table 4. An equivalent modification can be applied to UTRAN 102by adding the “PLMN of PGW/GGSN” IE by using a RANAP: RELOCATION REQUESTmessage.

In case of mobility for E-UTRAN 112 and UTRAN 102 not involving the CN(i.e., X2 or Iur based mobility), the new information may be added tothe respective mobility messages. For E-UTRAN 112 the X2 handoverprocedure is described in TS36.300 section 10.1.2.1.1. An equivalentprocedure, SRNS relocation, exists for UTRAN over the Iur interface.

For UTRAN 102, the new PLMN of PGW IE shall be added to the HANDOVERREQUIRED message to communicate to the target RAN the PLMN ID of the PGW120 associated with the handed over RAB. An example of how such new IEcould be included is shown in the Table 5: Example of inclusion of new“PLMN of PGW” IE in the X2: HANDOVER REQUIRED message (see TS36.423).

In the case of UTRAN 102, the new PLMN of PGW/GGSN IE shall be added inthe RNSAP: Enhanced Relocation Request message and in particular in theRANAP Enhanced Relocation Information Required IE defined in TS25.413.An example of how this could be achieved is shown in Table 6: Example ofinclusion of new “PLMN of PGW/GGSN” IE in the RANAP Enhanced RelocationInformation IE included in the RNSAP: Enhanced Relocation Requestmessage (see TS25.423).

The new information concerning the PLMN ID of the PGW 120/GGSN 110associated to the RAB handed over may be sent for each RAB.

The information added to the messages and procedures above shall not belimited to the PLMN ID of the PGW 120/GGSN 110 to which the RAB isassociated. Such information could include any indication that allowsthe RAN to understand the actions to be taken upon reception ofSIRIG-like marking. For example, the information added could consist ofan index pointing at a particular SIRIG policy, which allows the RAN tounderstand the RRM policy so as to apply packets with specific SIRIGmarking.

III. Example Network Node

FIG. 10 illustrates a block diagram of an example core network node. Asshown in FIG. 10, the core network node includes: a data processingsystem (DPS) 402, which may include one or more processors (P) 455(e.g., microprocessors) and/or one or more circuits, such as anapplication specific integrated circuit (ASIC), Field-programmable gatearrays (FPGAs), etc.; a network interface 403 for connecting the networknode to a network 130; a data storage system 406, which may include oneor more computer-readable data storage mediums, such as non-transitorymemory unit (e.g., hard drive, flash memory, optical disk, etc.) and/orvolatile storage apparatuses (e.g., dynamic random access memory(DRAM)).

In embodiments where data processing system 402 includes a processor 455(e.g., a microprocessor), a computer program product 433 may beprovided, which computer program product includes: computer readableprogram code 443 (e.g., instructions), which implements a computerprogram, stored on a computer readable medium 442 of data storage system406, such as, but not limited, to magnetic media (e.g., a hard disk),optical media (e.g., a DVD), memory devices (e.g., random accessmemory), etc. In some embodiments, computer readable program code 443 isconfigured such that, when executed by data processing system 402, code443 causes the data processing system 402 to perform steps describedherein.

In some embodiments, network node is configured to perform stepsdescribed above without the need for code 443. For example, dataprocessing system 402 may consist merely of specialized hardware, suchas one or more application-specific integrated circuits (ASICs). Hence,the features of the present invention described above may be implementedin hardware and/or software. For example, in some embodiments, thefunctional components of network node described above may be implementedby data processing system 402 executing program code 443, by dataprocessing system 402 operating independent of any computer program code443, or by any suitable combination of hardware and/or software.

While various aspects and embodiments of the present disclosure havebeen described above, it should be understood that they have beenpresented by way of example only, and not limitation. Thus, the breadthand scope of the present disclosure should not be limited by any of theabove-described exemplary embodiments. Moreover, any combination of theelements described in this disclosure in all possible variations thereofis encompassed by the disclosure unless otherwise indicated herein orotherwise clearly contradicted by context.

Additionally, while the processes described herein and illustrated inthe drawings are shown as a sequence of steps, this was done solely forthe sake of illustration. Accordingly, it is contemplated that somesteps may be added, some steps may be omitted, the order of the stepsmay be re-arranged, and some steps may be performed in parallel.

Tables

Table 1 is an example table of inclusion of new “PLMN of PGW/GGSN” IE ina RAB ASSIGNMENT REQUEST message (see TS25.413)). Table 2 is an exampletable of inclusion of new “PLMN of PGW/GGSN” IE in an INITIAL CONTEXTSETUP message (see TS36.413). Table 3 is an example table of inclusionof new “PLMN of PGW” IE in a E-RAB SETUP REQUEST message (seeTS36.413)). Table 4 is an example table of inclusion of new “PLMN ofPGW” IE in the HANDOVER REQUEST message (see TS36.413). Table 5 is anexample table of inclusion of new “PLMN of PGW” IE in the X2: HANDOVERREQUIRED message (see TS36.423). Table 6 is an example table ofinclusion of new “PLMN of PGW/GGSN” IE in the RANAP Enhanced RelocationInformation IE included in the RNSAP: Enhanced Relocation Requestmessage (see TS25.423). Table 7 is an example table of RAB AssignmentRequest message with new IE for PLMN ID. Table 8 is an example tableindicating an Initial Context Setup Request message with new IE for PLMNID). Table 9 is an example table indicating an E-RAB SETUP REQUEST withnew IE for PLMN ID.

TABLE 1 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject RABs To Be Setup Or O YES ignore Modified List  >RABs To Be SetupOr 1 to  Modified Item IEs <maxnoofRABs>  >>First Setup Or M GroupingEACH reject  Modify Item reason: same criticality.   >>>RAB ID M 9.2.1.2The same — RAB ID must only be present in one group.   >>>NAS O 9.2.3.18—   Synchronisation   Indicator   >>>PLMN of O 9.2.3.33 The PLMN  PGW/GGSN ID of the PGW/GGSN involved in the RAB assignment   >>>RABParameters O 9.2.1.3 Includes all — necessary parameters for RABs (bothfor MSC and SGSN) including QoS.   >>>User Plane O —   Information  >>>>User Plane M 9.2.1.18 —   Mode   >>>>UP Mode M 9.2.1.19 —  Versions   >>>Transport Layer O —   Information   >>>>Transport M9.2.2.1 —   Layer Address   >>>>Iu Transport M 9.2.2.2 —   Association  >>>Service Handover O 9.2.1.41 —   >>>E-UTRAN O 9.2.1.90 YES Ignore  Service Handover   >>>Correlation ID O 9.2.2.5 —  >>Second Setup Or MGrouping EACH Ignore  Modify Item reason: same criticality.   >>>PDPType O 9.2.1.40 —   Information   >>>Data Volume O 9.2.1.17 —  Reporting   Indication   >>>DL GTP-PDU O 9.2.2.3 —   Sequence Number  >>>UL GTP-PDU O 9.2.2.4 —   Sequence Number   >>>DL N-PDU O 9.2.1.33 —  Sequence Number   >>>UL N-PDU O 9.2.1.34 —   Sequence Number  >>>Alternative RAB O 9.2.1.43 YES Ignore   Parameter Values   >>>GERANBSC O 9.2.1.58 YES Ignore   Container   >>>PDP Type O 9.2.1.40a The PDPYES Ignore   Information extension Type Information extension IE canonly be included if PDP Type Information IE is not present.   >>>OffloadRAB O 9.2.1.94 Applicable YES Ignore   parameters only for SIPTO at Iu-PS. RABs To Be Released List O YES Ignore  >RABs To Be Released 1 toEACH Ignore  Item IEs <maxnoofRABs>  >>RAB ID M 9.2.1.2 The same — RABID must only be present in one group.  >>Cause M 9.2.1.4 — UE AggregateMaximum O 9.2.1.91 YES Ignore Bit Rate MSISDN O 9.2.1.95 Applicable YESIgnore only for SIPTO at Iu- PS.

TABLE 2 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject MME UE S1AP ID M 9.2.3.3 YES reject eNB UE S1AP ID M 9.2.3.4 YESreject UE Aggregate M 9.2.1.20 YES reject Maximum Bit Rate E-RAB to BeSetup 1 YES reject List  >E-RAB to Be Setup 1 . . . <maxnoofE- EACHreject  Item IEs RABs>  >>E-RAB ID M 9.2.1.2 —  >>E-RAB Level M 9.2.1.15Includes —  QoS Parameters necessary QoS parameters.  >>Transport LayerM 9.2.2.1 —  Address  >>GTP-TEID M 9.2.2.2 —  >>NAS-PDU O 9.2.3.5 — >>Correlation ID O 9.2.1.80 YES ignore  >>PLMN of O 9.2.3.8 The PLMNPGW ID of the PGW/GGSN involved in the RAB assignment UE SecurityCapabilities M 9.2.1.40 YES reject Security Key M 9.2.1.41 The KeNB isYES reject provided after the key- generation in the MME, see TS 33.401[15]. Trace Activation O 9.2.1.4 YES ignore Handover Restriction O9.2.1.22 YES ignore List UE Radio Capability O 9.2.1.27 YES ignoreSubscriber Profile ID O 9.2.1.39 YES ignore for RAT/Frequency priorityCS Fallback Indicator O 9.2.3.21 YES reject SRVCC Operation O 9.2.1.58YES ignore Possible CSG Membership Status O 9.2.1.73 YES ignoreRegistered LAI O 9.2.3.1 YES ignore GUMMEI O 9.2.3.9 This IE indicatesYES ignore the MME serving the UE. MME UE S1AP ID 2 O 9.2.3.3 This IEindicates YES ignore the MME UE S1AP ID assigned by the MME. ManagementBased O 9.2.1.83 YES ignore MDT Allowed Management Based O MDT YESignore MDT PLMN List PLMN List 9.2.1.89

TABLE 3 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject MME UE S1AP ID M 9.2.3.3 YES reject eNB UE S1AP ID M 9.2.3.4 YESreject UE Aggregate Maximum O 9.2.1.20 YES reject Bit Rate E-RAB to beSetup List 1 YES reject  >E-RAB to Be Setup 1 . . . <maxnoofE- EACHreject  Item IEs RABs>  >>E-RAB ID M 9.2.1.2 —  >>E-RAB Level QoS M9.2.1.15 Includes —  Parameters necessary QoS parameters.  >>TransportLayer M 9.2.2.1 —  Address  >>GTP-TEID M 9.2.2.2 EPC TEID. —  >>NAS-PDUM 9.2.3.5 —  >>Correlation ID O 9.2.1.80 YES ignore  >>PLMN of PGW O9.2.3.8 The PLMN ID of the PGW/GGSN involved in the RAB assignment

TABLE 4 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject MME UE S1AP ID M 9.2.3.3 YES reject Handover Type M 9.2.1.13 YESreject Cause M 9.2.1.3 YES ignore UE Aggregate Maximum M 9.2.1.20 YESreject Bit Rate E-RABs To Be Setup 1 YES reject List  >E-RABs To BeSetup 1 . . . <maxnoofE- EACH reject  Item IEs RABs>  >>E-RAB ID M9.2.1.2 —  >>Transport Layer M 9.2.2.1 —  Address  >>GTP-TEID M 9.2.2.2To deliver UL — PDUs.  >>E-RAB Level QoS M 9.2.1.15 Includes necessary — Parameters QoS parameters.  >>Data Forwarding O 9.2.1.76 YES ignore Not Possible  >>PLMN of PGW O 9.2.3.8 The PLMN ID of the PGW/GGSNinvolved in the RAB assignment Source to Target M 9.2.1.56 YES rejectTransparent Container UE Security Capabilities M 9.2.1.40 YES rejectHandover Restriction List O 9.2.1.22 YES ignore Trace Activation O9.2.1.4 YES ignore Request Type O 9.2.1.34 YES ignore SRVCC Operation O9.2.1.58 YES ignore Possible Security Context M 9.2.1.26 YES reject NASSecurity Parameters C- 9.2.3.31 The eNB shall use YES reject to E-UTRANiffromUTRANGERAN this IE as specified in TS 33.401 [15]. CSG Id O9.2.1.62 YES reject CSG Membership Status O 9.2.1.73 YES ignore GUMMEI O9.2.3.9 This IE indicates YES ignore the MME serving the UE. MME UE S1APID 2 O 9.2.3.3 This IE indicates YES ignore the MME UE S1AP ID assignedby the MME. Management Based MDT O 9.2.1.83 YES ignore AllowedManagement Based MDT O MDT YES ignore PLMN List PLMN List 9.2.1.89

TABLE 5 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.13 YESreject Old eNB UE X2AP ID M eNB UE Allocated at the YES reject X2AP IDsource eNB 9.2.24 Cause M 9.2.6 YES ignore Target Cell ID M ECGI YESreject 9.2.14 GUMMEI M 9.2.16 YES reject UE Context Information 1 YESreject  >MME UE S1AP ID M INTEGER MME UE S1AP — — (0 . . . 2³² − 1) IDallocated at the MME  >UE Security M 9.2.29 — —  Capabilities  >ASSecurity M 9.2.30 — —  Information  >UE Aggregate M 9.2.12 — —  MaximumBit Rate  >Subscriber Profile ID O 9.2.25 — —  for RAT/Frequency priority  >E-RABs To Be Setup 1 — —  List  >>E-RABs To Be 1 . . .<maxnoof EACH ignore  Setup Item Bearers>   >>>E-RAB ID M 9.2.23 — —  >>>E-RAB Level M 9.2.9 Includes — —   QoS Parameters necessary QoSparameters   >>>DL Forwarding O 9.2.5 — —   >>>UL GTP Tunnel M GTP SGWendpoint of — —   Endpoint Tunnel the S1 transport Endpoint bearer. For9.2.1 delivery of UL PDUs.   >>PLMN of PGW O 9.2.3.8 The PLMN ID of thePGW/GGSN involved in the RAB assignment  >RRC Context M OCTET Includesthe — — STRING RRC Handover Preparation Information message as definedin subclause 10.2.2 of TS 36.331 [9]  >Handover Restriction O 9.2.3 — — List  >Location Reporting O 9.2.21 Includes the — —  Informationnecessary parameters for location reporting  >Management Based O 9.2.59YES ignore  MDT Allowed  >Management Based O MDT YES ignore  MDT PLMNList PLMN List 9.2.64 UE History Information M 9.2.38 Same definitionYES ignore as in TS 36.413 [4] Trace Activation O 9.2.2 YES ignore SRVCCOperation O 9.2.33 YES ignore Possible CSG Membership Status O 9.2.52YES reject Mobility Information O BIT Information YES ignore STRINGrelated to the (SIZE handover; the (32)) source eNB provides it in orderto enable later analysis of the conditions that led to a wrong HO.

TABLE 6 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESignore Source RNC To M 9.2.1.28 YES reject Target RNC TransparentContainer Old Iu Signalling O 9.2.1.38 YES ignore Connection IdentifierCS domain Global CN-ID CS O 9.2.1.46 YES reject domain Old Iu SignallingO 9.2.1.38 YES ignore Connection Identifier PS domain Global CN-ID PS O9.2.1.46 YES reject domain RABs To Be Setup O YES reject List  >RABs ToBe 1 to <maxnoofRABs> EACH reject  Setup Item IEs  >>CN Domain M 9.2.1.5—  Indicator  >>RAB ID M 9.2.1.2 —  >>RAB M 9.2.1.3 —  Parameters >>Data C-ifPS 9.2.1.17 —  Volume  Reporting  Indication  >>PDP TypeC-ifPS 9.2.1.40 —  Information  >>>PLMN of O 9.2.3.33 The PLMN  PGW/GGSNID of the PGW/GGSN involved in the RAB assignment  >>User Plane M Information   >>>User M 9.2.1.18 —   Plane Mode   >>>UP Mode M 9.2.1.19—   Versions  >>Data O  Forwarding  TNL  Information   >>>Transport M9.2.2.1   Layer   Address   >>>Transport M Iu Related to   AssociationTransport TLA above. Association 9.2.2.2  >>Source Side O  Iu UL TNL Information   >>>Transport M 9.2.2.1 —   Layer   Address   >>>Iu M9.2.2.2 —   Transport   Association  >>Service O 9.2.1.41 —  Handover >>Alternative O 9.2.1.43 —  RAB Parameter  Values  >>E-UTRAN O 9.2.1.90YES ignore  Service  Handover  >>PDP Type O 9.2.1.40a The PDP YES Ignore Information Type  extension Information extension IE can only beincluded if PDP Type Information IE is present. SNA Access O 9.2.3.24YES ignore Information UESBI-Iu O 9.2.1.59 YES ignore Selected PLMN O9.2.3.33 YES ignore Identity CN MBMS O YES ignore Linking Information >Joined MBMS 1 to EACH ignore  Bearer Service<maxnoofMulticastServicesPerUE>  IEs  >>TMGI M 9.2.3.37 —  >>PTP RAB IDM 9.2.1.75 — Integrity Protection O 9.2.1.11 Integrity YES ignoreInformation Protection Information includes key and permittedalgorithms. Encryption O 9.2.1.12 Integrity YES ignore InformationProtection Information includes key and permitted algorithms. UEAggregate O 9.2.1.91 YES ignore Maximum Bit Rate RAB Parameters O9.2.1.102 Applicable YES reject List only to RNSAP relocation. CSG ID O9.2.1.85 Applicable YES reject only to Enhanced Relocation from RNCtowards a hybrid cell and RNSAP relocation. CSG Membership O 9.2.1.92Applicable YES reject Status only to Enhanced Relocation from RNCtowards a hybrid cell and RNSAP relocation. Anchor PLMN O 9.2.3.33Indicates the YES ignore Identity PS core network operator in case ofSRVCC (see TS 23.251 [39]).

TABLE 7 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject RABs To Be Setup Or O YES ignore Modified List  >RABs To Be Setup1 to  Or Modified Item IEs <maxnoofRABs>  >>First Setup Or M GroupingEACH reject  Modify Item reason: same criticality   >>>RAB ID M 9.2.1.2The same — RAB ID must only be present in one group.   >>>NAS O 9.2.3.18—   Synchronisation   Indicator   >>>RAB O 9.2.1.3 Includes all —  Parameters necessary parameters for RABs (both for MSC and SGSN)including QoS.   >>>User Plane O —   Information   >>>>User Plane M9.2.1.18 —   Mode   >>>>UP Mode M 9.2.1.19 —   Versions   >>>Transport O—   Layer   Information   >>>>Transport M 9.2.2.1 —   Layer Address  >>>>Iu M 9.2.2.2 —   Transport   Association   >>>Service O 9.2.1.41 —  Handover   >>>E-UTRAN O 9.2.1.90 YES ignore   Service Handover  >>>Correlation ID O 9.2.2.5 —   >>>PLMN of O YES ignore PGW/GGSN >>Second Setup Or M Grouping EACH ignore  Modify Item reason: samecriticality   >>>PDP Type O 9.2.1.40 —   Information   >>>Data Volume O9.2.1.17 —   Reporting   Indication   >>>DL GTP-PDU O 9.2.2.3 —  Sequence Number   >>>UL GTP-PDU O 9.2.2.4 —   Sequence Number   >>>DLN-PDU O 9.2.1.33 —   Sequence Number   >>>UL N-PDU O 9.2.1.34 —  Sequence Number   >>>Alternative O 9.2.1.43 YES ignore   RAB Parameter  Values   >>>GERAN BSC O 9.2.1.58 YES ignore   Container   >>>PDP TypeO 9.2.1.40a The PDP YES ignore   Information Type   extensionInformation extension IE can only be included if PDP Type Information IEis not present.   >>>Offload RAB O 9.2.1.94 Applicable YES ignore  parameters only for SIPTO at Iu-PS RABs To Be Released O YES ignoreList  >RABs To Be 1 to EACH ignore  Released Item IEs <maxnoofRABs> >>RAB ID M 9.2.1.2 The same — RAB ID must only be present in one group. >>Cause M 9.2.1.4 — UE Aggregate Maximum O 9.2.1.91 YES ignore Bit RateMSISDN O 9.2.1.95 Applicable YES ignore only for SIPTO at Iu-PS

TABLE 8 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject MME UE S1AP ID M 9.2.3.3 YES reject eNB UE S1AP ID M 9.2.3.4 YESreject UE Aggregate Maximum Bit M 9.2.1.20 YES reject Rate E-RAB to BeSetup List 1 YES reject  >E-RAB to Be Setup Item 1 to EACH reject  IEs<maxnoofE- RABs>  >>E-RAB ID M 9.2.1.2 —  >>E-RAB Level QoS M 9.2.1.15Includes necessary —  Parameters QoS parameters  >>Transport Layer M9.2.2.1 —  Address  >>GTP-TEID M 9.2.2.2 —  >>NAS-PDU O 9.2.3.5 — >>Correlation ID O 9.2.2.80 YES ignore  >>PLMN of PGW O YES ignore UESecurity Capabilities M 9.2.1.40 YES reject Security Key M 9.2.1.41 TheKeNB is YES reject provided after the key-generation in the MME, see TS33.401 [15] Trace Activation O 9.2.1.4 YES ignore Handover RestrictionList O 9.2.1.22 YES ignore UE Radio Capability O 9.2.1.27 YES ignoreSubscriber Profile ID for O 9.2.1.39 YES ignore RAT/Frequency priorityCS Fallback Indicator O 9.2.3.21 YES reject SRVCC Operation Possible O9.2.1.58 YES ignore CSG Membership Status O 9.2.1.73 YES ignoreRegistered LAI O 9.2.3.1 YES ignore GUMMEI ID O 9.2.3.9 This IEindicates the YES ignore MME serving the UE MME UE S1AP ID 2 O 9.2.3.3This IE indicates the YES ignore MME UE S1AP ID assigned by the MMEManagement Based MDT O 9.2.1.83 YES ignore Allowed

TABLE 9 IE type and Semantics Assigned IE/Group Name Presence Rangereference description Criticality Criticality Message Type M 9.2.1.1 YESreject MME UE S1AP ID M 9.2.3.3 YES reject eNB UE S1AP ID M 9.2.3.4 YESreject UE Aggregate Maximum O 9.2.1.20 YES reject Bit Rate E-RAB to beSetup List 1 YES reject  >E-RAB To Be Setup 1 to <maxnoof EACH reject Item IEs E-RABs>  >>E-RAB ID M 9.2.1.2 —  >>E-RAB Level QoS M 9.2.1.15Includes —  Parameters necessary QoS parameters  >>Transport Layer M9.2.2.1 —  Address  >>GTP-TEID M 9.2.2.2 EPC TEID —  >>NAS-PDU M 9.2.3.5—  >>Correlation ID O 9.2.2.80 YES ignore  >>PLMN of PGW O YES ignore

What is claimed is:
 1. A method in a communication system comprising afirst core network node (CN), a second CN, a base station apparatusserving a user equipment (UE), and a packet data network gateway (PGW)associated with the UE, the method being performed by the first CN andcomprising: the first CN receiving a tunneling endpoint identifier(TEID) information element from a second CN, the TEID informationelement comprises a plurality of fields, wherein one of said pluralityof fields includes a Public Land Mobile Network (PLMN) identifier of thePGW; and the first CN forwarding the received PLMN identifier to thebase station apparatus.
 2. The method of claim 1, wherein the TEIDinformation element is a fully qualified TEID (F-TEID) informationelement.
 3. The method of claim 1, wherein the base station apparatus isan enodeB (eNB).
 4. The method of embodiment 1, wherein: the basestation apparatus comprises a radio network controller (RNC) and a basestation, and forwarding the received PLMN identifier to the base stationapparatus comprises forwarding the PLMN identifier to the RNC.
 5. Themethod of claim 1, wherein the first CN is a serving general packetradio service support node (SGSN) and the second CN is a gateway generalpacket radio service support node (GGSN).
 6. The method of claim 1,wherein the first CN is an mobility management entity (MME) and thesecond CN is an signaling gateway (SGW).
 7. The method of claim 1,wherein said on of said plurality of fields of the information elementincludes a TEID/GRE Key field.
 8. A method in a communication systemcomprising an SGSN, a base station serving a user equipment (UE), an RNCcontrolling the base station, and a packet data network gateway (PGW)associated with the UE, the method being performed by the SGSN andcomprising: the SGSN obtaining a PLMN identifier (ID) of the PGW; andthe SGSN transmitting the PLMN ID to the RNC.
 9. A method in acommunication system comprising a first core network node (CN), a basestation apparatus serving a user equipment (UE), and a packet datanetwork gateway (PGW) associated with the UE, the method being performedby the first CN and comprising: the first CN obtaining a PLMN identifierof the PGW; and the first CN transmitting a message to the base stationapparatus, wherein the message comprises: i) an information elementcontaining the PLMN ID of the PGW and ii) a radio access bearer (RAB)identifier information element comprising data identifying a RAB. 10.The method of claim 9, wherein the message further comprises a messagetype information element indicating that the message is a RAB AssignmentRequest message.
 11. The method of claim 9, wherein the message furthercomprises a message type information element indicating that the messageis an Initial Context Setup Request message.
 12. The method of claim 9,wherein the message further comprises a message type information elementindicating that the message is a EUTRAN RAB (E-RAB) Setup Requestmessage.
 13. The method of claim 9, wherein the message furthercomprises a message type information element indicating that the messageis a Handover Request message.
 14. The method of claim 9, wherein thefirst CN is an MME.
 15. The method of claim 9, wherein the RAB is anE-RAB.
 16. The method of claim 9, further comprising: the base stationapparatus transmitting to a source MME a handover message comprising thePLMN ID of the PGW; the source MME transmitting to a target MME arelocation request message comprising the PLMN ID received by the sourceMME in the handover message; and the target MME transmitting to a targetbase station apparatus a message comprising the PLMN ID the target MMEreceived from the source MME via the relocation message.
 17. A method ina communication system comprising a first core network node (CN), asecond CN, and a packet data network gateway (PGW) associated with userequipment (UE), the method being performed by the first CN andcomprising: the first CN encoding a Public Land Mobile Networkidentifier (PLMN ID) of the PGW in a TEID/GRE Key field of a F-TEIDinformation element; and the first CN transmitting the F-TEIDinformation element containing the PLMN ID to the second CN.
 18. Themethod of claim 17, wherein the first CN is a SGW and the second CN isan MME.
 19. The method of claim 17, further comprises the second CNtransmitting the received PLMN ID to a base station apparatus servingthe UE.
 20. The method of claim 17, wherein the step of transmitting theF-TEID information element to the second CN comprises transmitting acreate session response, including the F-TEID information element, tothe second CN; and the method further comprises: prior to the first CNencoding the PLMN ID in the TEID/GRE key field, the first CN receiving acreate session request message from the second CN, wherein the createsession request identifies the PGW.